Rust-proofing iron, steel, &amp;c.



No. 881,221. PATENTED MAR, 10, 1908.

A. 'BONTEMPI. v RUST PROOPING' IRON, STEEL, 6w.

APPLICATION IILED JAIL 29, 1907. RENEWED (AN. 28, 1908.

INVENTOR v by "If/111: 5, i aw mw LM WITNESSES:

UNITED AUGUSTO BONTEMPI, or NEW YORK, N. r.

RUST-PROOFING IRON, STEEL, 800.

Specification of Letters Patent.

Patented March 10, 1908.

Application filed January 29, 1907, Serial No. 354,672. Renewed January28, 1908. Seral No. 412,991.

To all whom it may concern:

.Be it known that I, AUcUs'ro BONTEMPI, a subject of the King of Italy,residing in the borough of Manhattan, city, county, and State of NewYork, have invented certain new and useful Improvements in Rust-ProofmgIron, Steel, or the Like, of which the following is a specification.

' The object of the invention is to produce a surface which preventsrusting even under severe conditions such as subjection to hightemperature and corrosive influence, water, salt water, etc. 7 j

The invention provides certain improvements over the method described inmy prior application No. 285,240 dated October 31, 1905 and adapted alsofor use in connection with the process of said application.

The desired effect is obtained by heating the iron to approximately from1000 degrees F. to 1800 degrees F. in a closed and preferably airtightchamber, the iron having een previously treated according to the'Bower-Barff process or not asdesired, and

subjecting it to the gas or vapor of one or more non-corrodiblesubstances. Where the BowerBarff treatment is omitted the temperatureneed .be only high enough'to insure volatilization of the non corrodiblesub stance. For example for zinc, lead and other volatile non-corrodiblemetals the temperature will generally be within 1000 degrees F.

At the time of applying the gases the metal under treatment will be verymuch expanded by the heat and the pores, especially those at the surfacewill be opened to receive the gases which will penetrate to aconsiderable de th depending upon the period of time and ot orconditions. When the metal cools after the treatment, the vapors arefirst reduced to a solid condition, and by the further cooling of themetal a very dense and substantiallynon-corrodible surface is produced.

Wherever heavy goods are being treated they will usually be subjected tothe Bower- Barfi process first. But for light flexible goods theBower-Barfi process may be omitted, the resulting coating being less,brittle by reason of the omission.

Where the goods are first subjected to steam according to theBower-Barri process, lime :or some equivalent alkaline material may beintroduced serving to insure a perfect dryness ,of the steamand-particularly also facilitating the formation of the coating by acatalytic action. I may also inject with the steam a small quantity ofnaphtha or other hydrocarbon which gives a desirable black color to thecoating.

The goods under treatment are preferably carried in a closed metalchamber with a surrounding chamber of firc brick. here the goods are notintended for the hardest use, however, the goods need not be carried ina perfectly airtight chamber but may be in an o wen pan within thechamber of fire brick whic l is comparatively tight.-

A suitable apparatus for carrying out the process is illustrateddiagrammatically in the drawings.

Referring to the drawings, A is the boiler furnishing the desired steam,which passes by a pipe to a coil C running back and therefore in thechamber D of fire brick and arranged on three sides of the sheet iron orsteel mufller orchamber E in which the goods to be treated, such as theipe F, are carried. A fire box G is arranged slow the chamber D, theproducts of combustion being carried by any suitable arrangement offines about A tray of lime H may be introduced into i the muflier beforethe latter is closed and heated. A branch J permits the injection ofnaphtha into the steam. p

Any suitable means such as' the pipe K may be used for introducing thenon-corro dible materials after the goods are heated to the desired hightemperature.

Where treatment by steam is not to be used in any particular case, ofcourse, it will not be necessary to use anythingmore than the mufllerwith means for heating it and for introducing the non-corrodiblematerials. Supposing, however, that the process is to comprise all thevarious steps'described, the operation is -as follows :The goods arefilled into the mufller which is placed in the fire brick chamber andthe latter substantially sealed after making the several connections.The muflier and contents are heated to from 1000 to 1800 degreesFahrenheit a proximately and then the steam from theoiler A isintroducedand the rocess continued until the usual black-oxid s produced to thedesired depth. Thereu on, While maintaining the temperature of't emuffler, the steam is ,cut off and the non-corrodible materialmtroduced.

As examples offthe non-corrodible mateand then with the hydrocarbon. 2O

\ tic-ularity of detail certain specific embodirial, I may use (1)tannic acid, an oleaginous I material, and a non-corrodible metal suchas zinc or an oxid of such metal; or (2) a pure 5 metal such as zinc orlead; or (3) substantially solid hydrocarbons such as coal tar or pitch.The first of these compositions gives a good coating of dark gray color,the second gives also a good coating of blue color, but the third givesa black coating of the very 5 highest quality. I have tested goods madewith this black coating under all known con- 1 ditions for rusting andhave found them to f be perlectlv rust proof under all tests.

()f the three non-corrodible materials above described the best resultsare obtained by treatment first with the non-corrodible metal (eitheralone or in the combination with tannic acid and oleaginous material)The process will be continued from 2- to 6 hours according to the depthof treatment desired and the weight of the goods, having regard to theweakening of the fiber which might be serious in light goods.

Before the treatment the metal is washed perfectly clean as usual inrust proofing processes. After the goods are taken out of the retortthey are cooled to about 100 degrees F. and greased with Vaseline andcleaned so as to give them a good polish and of attractive appearance.

Although I have described with great parments of my invention, yet it isnot to be understood therefrom that the invention is restricted to theparticular embodiments disclosed, as various modifications thereof indetail may be made by those skilled in the art' without departure fromthe invention.

What I claim is:

1. The method of protecting iron or steel which consists in sub ectingit to the Bower- Bartf treatment and subsequently subjecting it to thevapor or gas of a non-corrodible metal substance while heating it to ahigh temperature in a closed chamber.

2. The method of protecting iron or steel which consists in subjectingit to the Bower- Barl'l treatment, and then subjecting it to the vaporor gas of a non-corrodible metal substance wlule heated in a closedchamber,

3 and finally subjecting it to the vapor or gas ola hydrocarbon whileheated in a c osed chamber, the temperatures in such closed chambersbeing in each case suliiciently high to form the vapor or gas referredto.

3. The method of )rotecting iron or steel which consists in su jectingit in a closed chamber at a temperature sullicient to form such a vaporor gas, to the vapor or gas of a composition including tannic acid, anoleaginous material, and an oxid of a non-corrodible metal.

4. The method of )rotecting iron or steel which consists in subjectingit in a closed chamber at a temperature suflicient to form such a vaporor gas, to the vapor or gas of a composition including tannic acid, anoleaginous material, and an oXid of a non-corrodible metal, andfollowing this by similar treat ment with a solid hydrocarbon.

In witness whereof, I have hereunto signed my name in the presence oftwo subscribing witnesses.

AUGUSTO BONTEMPI. Witnesses:

DOMINGO A.Us1NA, FRED WHITE

